2022-10-10 08:22:28

by Bixuan Cui

Subject: [PATCH -next] jbd2: use the correct print format

The print format error was found when using ftrace event:
<...>-1406 [000] .... 23599442.895823: jbd2_end_commit: dev 252,8 transaction -1866216965 sync 0 head -1866217368
<...>-1406 [000] .... 23599442.896299: jbd2_start_commit: dev 252,8 transaction -1866216964 sync 0

Print transaction and head with the unsigned format "%u" instead.

Fixes: 879c5e6b7cb4 ('jbd2: convert instrumentation from markers to tracepoints')
Signed-off-by: Bixuan Cui <[email protected]>
---
include/trace/events/jbd2.h | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/trace/events/jbd2.h b/include/trace/events/jbd2.h
index 99f783c..ce9accb 100644
--- a/include/trace/events/jbd2.h
+++ b/include/trace/events/jbd2.h
@@ -40,7 +40,7 @@
TP_STRUCT__entry(
__field( dev_t, dev )
__field( char, sync_commit )
- __field( int, transaction )
+ __field( tid_t, transaction )
),

TP_fast_assign(
@@ -49,7 +49,7 @@
__entry->transaction = commit_transaction->t_tid;
),

- TP_printk("dev %d,%d transaction %d sync %d",
+ TP_printk("dev %d,%d transaction %u sync %d",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->transaction, __entry->sync_commit)
);
@@ -97,8 +97,8 @@
TP_STRUCT__entry(
__field( dev_t, dev )
__field( char, sync_commit )
- __field( int, transaction )
- __field( int, head )
+ __field( tid_t, transaction )
+ __field( tid_t, head )
),

TP_fast_assign(
@@ -108,7 +108,7 @@
__entry->head = journal->j_tail_sequence;
),

- TP_printk("dev %d,%d transaction %d sync %d head %d",
+ TP_printk("dev %d,%d transaction %u sync %d head %u",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->transaction, __entry->sync_commit, __entry->head)
);
--
1.8.3.1

2022-10-10 14:38:07

by Jason Yan

Subject: Re: [PATCH -next] jbd2: use the correct print format

Hi Bixuan,

On 2022/10/10 16:09, Bixuan Cui wrote:
> The print format error was found when using ftrace event:
> <...>-1406 [000] .... 23599442.895823: jbd2_end_commit: dev 252,8 transaction -1866216965 sync 0 head -1866217368
> <...>-1406 [000] .... 23599442.896299: jbd2_start_commit: dev 252,8 transaction -1866216964 sync 0
>
> Print transaction and head with the unsigned format "%u" instead.
>
> Fixes: 879c5e6b7cb4 ('jbd2: convert instrumentation from markers to tracepoints')
> Signed-off-by: Bixuan Cui <[email protected]>
> ---
> include/trace/events/jbd2.h | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/include/trace/events/jbd2.h b/include/trace/events/jbd2.h
> index 99f783c..ce9accb 100644
> --- a/include/trace/events/jbd2.h
> +++ b/include/trace/events/jbd2.h
> @@ -40,7 +40,7 @@
> TP_STRUCT__entry(
> __field( dev_t, dev )
> __field( char, sync_commit )
> - __field( int, transaction )
> + __field( tid_t, transaction )

While you are at it, can you make all the tid tracing consistent. Some
tracing points using unsigned long such as:

TRACE_EVENT(jbd2_handle_extend,
TP_PROTO(dev_t dev, unsigned long tid, unsigned int type,
unsigned int line_no, int buffer_credits,
int requested_blocks),

TP_ARGS(dev, tid, type, line_no, buffer_credits, requested_blocks),


and the caller passing transaction->t_tid which is tid_t(unsigned int).

trace_jbd2_handle_extend(journal->j_fs_dev->bd_dev,
transaction->t_tid,
handle->h_type, handle->h_line_no,
handle->h_total_credits,
nblocks);

Thanks,
Jason

> ),
>
> TP_fast_assign(
> @@ -49,7 +49,7 @@
> __entry->transaction = commit_transaction->t_tid;
> ),
>
> - TP_printk("dev %d,%d transaction %d sync %d",
> + TP_printk("dev %d,%d transaction %u sync %d",




> MAJOR(__entry->dev), MINOR(__entry->dev),
> __entry->transaction, __entry->sync_commit)
> );
> @@ -97,8 +97,8 @@
> TP_STRUCT__entry(
> __field( dev_t, dev )
> __field( char, sync_commit )
> - __field( int, transaction )
> - __field( int, head )
> + __field( tid_t, transaction )
> + __field( tid_t, head )
> ),
>
> TP_fast_assign(
> @@ -108,7 +108,7 @@
> __entry->head = journal->j_tail_sequence;
> ),
>
> - TP_printk("dev %d,%d transaction %d sync %d head %d",
> + TP_printk("dev %d,%d transaction %u sync %d head %u",
> MAJOR(__entry->dev), MINOR(__entry->dev),
> __entry->transaction, __entry->sync_commit, __entry->head)
> );
>

2022-10-11 11:37:24

by Bixuan Cui

Subject: Re: [PATCH -next] jbd2: use the correct print format

在 2022/10/10 22:35, Jason Yan 写道:
> While you are at it, can you make all the tid tracing consistent. Some
> tracing points using unsigned long such as:
>
> TRACE_EVENT(jbd2_handle_extend,
>     TP_PROTO(dev_t dev, unsigned long tid, unsigned int type,
>          unsigned int line_no, int buffer_credits,
>          int requested_blocks),
>
>     TP_ARGS(dev, tid, type, line_no, buffer_credits, requested_blocks),
>
>
> and the caller passing transaction->t_tid which is tid_t(unsigned int).
>
>     trace_jbd2_handle_extend(journal->j_fs_dev->bd_dev,
>                  transaction->t_tid,
>                  handle->h_type, handle->h_line_no,
>                  handle->h_total_credits,
>                  nblocks);

Ok, I'll send another patch to fix this problem.


Thanks

Bixuan Cui